What should my max c.o.l. be...???


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husbandofaromanian
July 20, 2013, 11:12 AM
I am about to handload for my .223 Contender pistol (MGM barrel 1-7 twist)...
I am using Sierra 80-grain bullets into .223 Lapua brass... Loading data calls for 2.550 oal... I put a bullet into a new case and closed the action... my test round came out at 2.545... From what I have read researching my maximum col should be about 2.51... Any thoughts...???

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witchhunter
July 20, 2013, 01:13 PM
Seat a dummy round very long. One that it too long to close your contender. Keep seating it deeper until it barely closes, then use a marker to color the ogive of the bullet and check for rifling marks. Keep seaing it deeper until they just disappear. Measure your OAL, this is your "zero" for that bullet. I back off .010 and begin there. Start loading using the low end of the data and work up until best accuracy. If you change bullets, you must to this for each different bullet. Then try different seating depths until you are satisfied with the accuracy.

ranger335v
July 20, 2013, 04:41 PM
"Any thoughts...???"

Yeah. The only "research" that matters is what you do with your own rifle.

There's nothing fixed by any loading manual, if they give an OAL at all it's just what they used in their rifle to develope their data. Your rifle is diifferent, so will be your best OAL. Their OAL is no more a law for anyone else than their powder charges.

JohnM
July 20, 2013, 05:11 PM
Their OAL is no more a law for anyone else than their powder charges.

That's real good to tell someone!
So this one particular load I got gives a max of say 5 grains of Unique for such and such bullet, but there's enough room in the case for 20 or more, so I can just go ahead and stuff her full?

WHUT!?!

Reloadron
July 20, 2013, 08:01 PM
I would go about this as witchhunter suggested in post #2.

On another note the Sierra loading manual when it comes to their 80 grain Match King HPBT does mention an OAL of 2.550", however, they go on to say the test firearm was a Colt AR-15A2 with a 20" 1:7 twist. They go on to say "The data was fired in a NATO chamber, which will accept a cartridge OAL (with the 80 grain Match King) of 2.550". That is from their rifle loading data. The important thing here with the 2.550" OAL is the chamber being able to accept that OAL.

Their handgun loading manual uses a TC Contender but with a TC barrel 14" 1:12 twist. They never get an OAL above 2.250" or above a 63 grain bullet. Obviously with your barrel this is not the case. Your 1:7 twist should work out great for the 80 grain Match King bullets.

From what I have read researching my maximum col should be about 2.51... Any thoughts...???

Don't know where you got that? However, the reference to the OAL of 2.550 is based on an animal other than what you have.

You did get a OAL of 2.545" with a test round using the method suggested by witchhunter so I would back that down to an OAL of 2.535" and work from there. You need to keep in mind you are seating .020" deeper than the 2.055" OAL and this will in turn produce higher pressures than the 2.055" OAL would give you. How much higher pressure I really don't know. Start low and look for any high pressure signs and you should be fine.

This is my guess as to the OAL discrepancy you are seeing and noted. I don't see it as unusual at all. You could also call the guys who made the barrel for some suggestions, I am sure they get such calls all the time. Finally if you are really curious you could make a chamber casting to see exactly what you have but I see no real need for that.

Ron

ranger335v
July 20, 2013, 09:03 PM
John, I don't want to jar your sensitivities but you seem to have a reading comprehension problem. Not a single thing in your post relates to Husband's question nor my answer to his question. :confused:

husbandofaromanian
July 20, 2013, 09:11 PM
I put a loose bullet in a new case... I closed the action and let it push the bullet into the case... Then I measured the length of the cartridge... 2.545... I found an old post (2008) talking about Centender pistols talking about this meathod... The poster suggested starting at .030 from that length...

So today I loaded 1 round with 23 grains of FME223 and shot it with the suppressor off to make sure it did not keyhole (stabilized)... It was...

Then I loaded 3 rounds with 23.6 grains of FME223 and shot through my suppressor and my chrono for velocity... I got 2322, 2335, 2310... This is throgh my 13" pistol barrel...

Tomorrow I will shoot for accuracy with this beginning load...

My reason for my original post is that I was concerned that I could not achieve the 2.550 col listed in the data I found...

Reloadron
July 20, 2013, 09:19 PM
There you go and off to a good start. Starting .010 or .030 back is a matter of what works best for your gun and apparently you had no pressure issues. Now just a matter of working up loads and in time you can even move the seating depth out and see what that gets you in the accuracy scheme of things. No need for concern as to the initial 2.550" OAL as we know where it was derived from. The gun itself as built should perform very well using those 80 grain Match King bullets.

Don't hesitate to post the accuracy as you have me curious what it will do.

Ron

husbandofaromanian
July 20, 2013, 09:19 PM
my c.o.l. for the above shooting was 2.515...

witchhunter
July 21, 2013, 12:00 AM
If you smashed a long one and measured it, then set your seater to that measurement, just mark one more seated to that length, it could still be touching the lands. It is useful to know what your length is just touching the lands, if you decide to seat into the lands more, remember to back off to starting data on powder. Seating on or in the lands can cause pressure spikes from nowhere.

JohnM
July 21, 2013, 06:48 AM
ranger335v----
Read the end of your idiotic statement.

ranger335v
July 21, 2013, 09:03 AM
"ranger335v---- Read the end of your idiotic statement. "

Okay, I did. Now what?

Is it seriously your belief that book info - OAL or powder charge - is a law which can be accepted with blind faith, now and forever, with any combo of firearms and components? If so, you believe somthing the book makers don't! That's why they ALL say, "Start low and slowly work up to listed max UNLESS over pressure signs occur earlier." If you think a book max of anything is "safe" simply because it's listed in the book you still have too much to learn to be advising others on the net. :cool:

I stand behind what I said, no book value of anything is a law to be blindly accepted. What do you stand behind? :banghead:

husbandofaromanian
July 21, 2013, 11:27 AM
I just feel happy to have found some powder finally... I knew nothing about this CFE223 until I found it in a store... Looks like a pretty good powder... Since my velocities aren't real fast to start with, I might get the copper free experience... Pressure signs are a big concern to me... I'm pushing the envelope with this pistol...

ranger335v
July 21, 2013, 07:41 PM
Forget book OALs, it's just what they used to develop their data in their rifle, and find your own MAX OAL as post #2 suggested.

You have a small cartridge so start loading 2-3 rounds each at book charge minimums and work up in maybe .3 grain steps to find your most accurate load range - without signs of over pressure, but not exceeding book max, as your manual will tell you.. You should see a pattern where the groups slowly get smaller and then begin to increase; go back to the better shooting range and try a few more around that point.

Then start experiments in seating by setting the bullets deeper in maybe 5 thou steps until you fine tune to the best OAL, thay may be as much as 30 thou off the lands - or more. If your barrrel likes your bullet it shouldn't take long to obtain all the barrel - and you - are capabile of producing. If your barrel doesn't like your bullet there's no way you gonna get it to shoot well.

Good luck! :)

steve4102
July 21, 2013, 10:13 PM
Ranger has it right, OAL is Firearm and bullet specific, NOT manual specific.

He is also correct about powder charge as load data is not a recipe, only a guideline. Start Low and Work up to Max, and do not exceed max. Work up means exactly that, work up slowly looking for accuracy and pressure signs.

If Load data and their Max loads were an absolute and written in stone, then all manuals would be identical and working up would be unnecessary as far as pressure and safety goes.

JohnM
July 22, 2013, 07:15 AM
Couple you super experts want to think your so cool carrying interpretation of powder load specs to extremes have at it. Guess we can all just throw out a few dozen manuals apiece and wing it.
I don't need to be around here.

steve4102
July 22, 2013, 10:33 AM
Couple you super experts want to think your so cool carrying interpretation of powder load specs to extremes have at it. Guess we can all just throw out a few dozen manuals apiece and wing it.
I don't need to be around here.

Sorry to see you go, but before you do. Take a look at Nolser #6 loading manual. They don't even list the OAL tested, it is that unimportant. On page 43 of #6 they instruct the handloader to find the Max OAL for their particular firearm and bullet of choice, then reduce this Max OAL by .015-.030 and work up the loads.

ranger335v
July 22, 2013, 05:39 PM
"Sorry to see you go, but before you do. Take a look at Nolser #6 loading manual. They don't even list the OAL tested,..."

When I started reloading virtually no one spoon fed us an OAL. That started much later to give nervous noobs a little reassurance, now it seems to be interpreted as "Do it this way or die"; well, no one of my generation pays any attention to book OAL and I know of none of us who died or even blew off any fingers because we always followed "book instructions" to "start low, work up..." etc.

I do know of some newer guys (magazine experts?) who've done damage by thinking anything in a book, wether OAL or powder charges, has to be safe...or even "lawyered down" a bit - which is pure BS. I believe anyone thinking otherwise or is too immature to take obvious correction without whining is better gone from here, not advising others.

steve4102
July 22, 2013, 06:48 PM
When I started reloading virtually no one spoon fed us an OAL. That started much later to give nervous noobs a little reassurance, now it seems to be interpreted as "Do it this way or die"; well, no one of my generation pays any attention to book OAL and I know of none of us who died or even blew off any fingers because we always followed "book instructions" to "start low, work up..." etc.

I do know of some newer guys (magazine experts?) who've done damage by thinking anything in a book, wether OAL or powder charges, has to be safe...or even "lawyered down" a bit - which is pure BS. I believe anyone thinking otherwise or is too immature to take obvious correction without whining is better gone from here, not advising others.

Very well said. To Bad your wisdom and logic falls on far to many a deaf ear.
Call on.

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